Typical case of CO2 capture in Chinese iron and steel enterprises: Exergy analysis

The iron and steel industry is not only a major energy consumer but also a major CO2 emitter. Thus, this industry is now actively improving its energy utilization efficiency and reducing carbon emissions in the production process through process development, equipment upgrades, and CO2 capture and utilization. Based on typical CO2 capture and utilization cases in Chinese iron and steel enterprises, this study analyzes the exergy efficiencies and exergy losses of different CO2 capture processes, confirming that the main reasons for low exergy efficiencies and large exergy losses in such processes are the consumption of steam, electricity, and converter gas, and further analyzes the impacts of converter gas and steam recycling on the exergy efficiency of CO2 capture. The results show that the product exergy efficiency of the C-PRO-4 process is increased by 19.97% compared with that before recycling, and 21.35%, 24.4%, and 6.8%, respectively, compared with those of the C-PRO-1, C-PRO-2, and C-PRO-3 processes after recycling, providing data reference for improving energy utilization in CO2 capture.

Automated summary

The iron and steel industry is actively improving energy utilization efficiency and reducing carbon emissions through process development, equipment upgrades, and CO2 capture and utilization. This study analyzes the exergy efficiencies and losses of different CO2 capture processes, identifying steam, electricity, and converter gas consumption as main factors affecting exergy efficiency. The analysis also highlights the positive impact of converter gas and steam recycling on exergy efficiency, providing valuable data for improving energy utilization in CO2 capture.